Acyloxy Fluoroalkoxy Tellurium Oxides

Acyloxy(2,2,3,3-tetrafluoropropoxy) tellurium oxides were formed upon heating bis[acyloxy] tellurium bis[fluoroalkoxides] under a vacuum of 0.01 torr.  

The acyloxy fluoroalkoxy tellurium oxides have low solubilities in organic solvents. Upon storage fluoroalkoxy carboxylates are slowly eliminated. When mixed with diethyl ether, tellurium dioxide and the ester are rapidly formed. Heating under 0.015 torr with a Bunsen burner causes decomposition to tellurium dioxide . 

When 12 mmol of a carboxylic acid anhydride were gradually added to 6 mmol of tellurium tetrakis[2,2,3,3-tetrafluoropropoxide], bi acyloxy] tellurium bis fluoroalkoxides] were formed as moisture-sensitive, colorless crystals or oils . 

Tellurium tetrakis[fluoroalkoxides] mixed with an equimolar amount of a carboxylic anhydride at 0°, and the mixture kept at 20° for two hours, produced moisture-sensitive acyloxy tellurium tris fluoroalkoxides]. The trifluoroalkyl carboxylates were removed under vacuum, the products washed several times with hexane-benzene (5 1), and the washed material dried in vacuo.  

Irgolic Organo-tellurium Compounds without a C,Te-Bond 

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When the bis[acyloxy] tellurium bis[fluoroalkoxidcs] were heated under 0.01 torr, acyloxy fluoroalkoxy tellurium oxides were formed (see p. 94). 

When the acyloxy tellurium tris[fluoroalkoxides] were heated at 80° under a vacuum of 0.01 torr, fluoroalkoxy carboxylates were eliminated with formation of bis[fluoroalkoxy] tellurium oxides (see p. 93). 

Depending on the nature of the anhydride, the ratio of the reagents, and the reaction temperature, tellurium tetrakis[fluoroalkoxides] and carboxylic acid anhydrides reacted to yield fluoroalkyl carboxylates, tellurium dioxide, acyloxy tellurium tris[fluoroalkoxide], bis[acyloxy] tellurium bis[fluoroalkoxides], tetrakis[acyloxy] tellurium compounds, or bis[fluoroalkoxy] tellurium oxides. ... 

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